Election fever looked set to dominate the Labour party conference again today as Gordon Brown's top cabinet ally inadvertently fuelled speculation.

Ed Balls, the schools and families secretary, made every attempt to evade the issue when asked about the prospect of snap poll next month.

But pressed on whether the prime minister was likely to risk an election in October or November, Mr Brown's right-hand man for more than a decade questioned whether the bigger gamble was to go to the country now, while Labour is riding high in the opinion polls, or wait until next year or beyond.

"It's a very interesting question as to where the gamble really lies," he said.

The prime minister is thought to be mulling over the impact of this week's gathering of Labour party members in Bournemouth before making a decision.

Mr Balls said: "I think Gordon Brown will be looking very carefully at the events of this week."

His comments follow heightened speculation about the prospect of an early election amid increasingly favourable polls and a generally favourable response to Mr Brown's first conference speech as leader on Monday.

Constitutionally, Mr Brown does not need to call an election until spring 2010.

Pressed further on "where the gamble lay", Mr Balls said: "Clearly, over the last few months as Gordon Brown has established his leadership, as he's dealt with some of the difficult crises which have been thrown at him and at our country ... not only did public opinion polls strengthen but underlying support for his leadership has strengthened as well."

But he added: "I think the priority for him is that the country knows that his priority is delivering on their priorities."